Regional creatine kinase, adenylate kinase, and lactate dehydrogenase in normal canine brain.

Abstract

Following acute stroke, creatine kinase and other enzymes are released into the cerebrospinal fluid and blood from injured brain tissue. To determine whether regional differences in brain enzyme activity might exist and therefore affect the amount of enzyme released, we quantified the levels of creatine kinase, adenylate kinase, and lactate dehydrogenase in 12 regions of normal canine brain (n = 4). Adenylate kinase activity varied the least among regions (49 ±7 units/g), followed by lactate dehydrogenase activity (122 ±28 units/g). The pattern for both adenylate kinase and lactate dehydrogenase was higher activity in predominantly gray matter areas, lower activity in white matter, and intermediate activity in mixed regions. The distribution of creatine kinase brain isoenzyme and mitochondrial creatine kinase in canine brain was less predictable, showing wider variations among regions (isoenzyme, 462 ±116 units/g; mitochondrial, 42 ±20 units/g). Even cerebral gray matter demonstrated substantial regional variations in creatine kinase brain isoenzyme, ranging from 606 units/g in the parietal cortex to 329 units/g in the temporal cortex. We conclude that the content of creatine kinase brain isoenzyme varies more than twofold among areas of brain. This regional variation may be important in the interpretation of creatine kinase brain isoenzyme measurements in cerebrospinal fluid and serum used to assess neurologic injury following stroke. (Stroke

Intracellular compartmentation, structure and function of creatine kinase isoenzymes in tissues with high and fluctuating energy demands: the ‘phosphocreatine circuit’ for cellular energy homeostasis

“…Regional and cellular compartmentation. CK is an abundant enzyme in the entire brain, but microdissection studies already pointed to the existence of regional differences in CK content and PCr concentrations, with CK activity varying more than two-fold among different areas of the brain (Chandler et al, 1988). In cerebellar cortex, especially in the molecular layer, higher levels of CK and PCr were measured than in white matter (Maker et al, 1973).…”

Functional Aspects of Creatine Kinase in Brain

“…Regional variations in CK activity with comparably high levels in the cerebellum were re ported in studies using native isoenzyme electrophoresis [51] or enzymatic CK activity measurements of either tissue extracts [52] or cultured brain cells [53]. In particu lar, the molecular layer of the cerebellar cortex contains high levels of CK activity [40,52,54], In contrast, high levels of CK activity or messenger RNA levels of CK were shown in cultured oligodendrocytes [53,55], represent ing a model for developing oligodendrocytes in vivo.…”

Dynamic 13C MR spectroscopy as an alternative to imaging for assessing cerebral metabolism using hyperpolarized pyruvate in humans

“…MCT transportation to astrocytes and neurons is not likely further limited as they express sufficient MCT2 and MCT4 (Km = 3.5–28 mM) 32,39 . We correlated GM, WM, and CSF volumes with HP signals because the tissue compartments have distinctive characteristics in perfusion, MCT, enzyme activities, and intrinsic metabolite pool sizes 39–43 . Measured HP signals of pyruvate, lactate, and within the prescribed brain slices were largely proportional to GM and WM volumes within the slice.…”